Interviews are a great opportunity for you to shine. I was in the first scheduled group of interviewees last year with four other individuals. The interview process was a day long event (from ~8am-2pm but don't quote me). It was very relaxing, and a welcoming opportunity to learn more about the school, faculty, and the program itself. We started with a general Q&A and then were directed to the Library to take a small writing test to assess our competency and get some insight to our character. We then received a campus tour, and boxed lunch while listening to financial aid and other various campus organizations. We were then taken to a lobby to await our interviews. The interviews were closed file, and were conducted by 2 or 3 interviewers for the respective program you wish to matriculate to. The interview was very easy going, and just mainly focused on getting to know you in more depth. After the interview you are free to go, and will usually hear back within a few weeks.
Being the charter class meant many of us were being interviewed about two weeks before starting the program since interviews had started late in the season. However, I don't think that will be the case this year, as the timeline has improved.
Sorry for the long read, but I hope that answered your question.
-Alex